In vehicles with supercharged internal combustion engines, it is possible to increase the maximum available torque over a brief time period by means of an overboost function. Such an increase in torque can be achieved in certain driving situations, for example in the case of full load or kickdown. The term “overboost” is used to refer to a function which permits the maximum engine torque to be increased for a brief time period during strong acceleration. In this context, the charged pressure is briefly increased above the normal value.
Such an overboost phase or overboost function is, however, possible only over a brief time period since otherwise overheating of the supercharger occurs. Therefore, after an overboost phase a defined regeneration time for the supercharger is necessary in order to avoid corresponding damage to the supercharger. The maximum torque made available by the overboost function is therefore available only for a brief time period.
Hybrid vehicles are known. As well as a conventional internal combustion engine, they have at least one additional electric drive so that the vehicle can be optionally driven via the internal combustion engine or the at least one electric drive and/or together by means of both driving modes. In the present case, the vehicle in question is a hybrid vehicle which has a supercharged internal combustion engine with an overboost function in addition to the at least one electric drive.